What happens when a client's MAC address does not match the router's whitelist?

• A. Access is granted, and the client can join.
• B. Access is denied, and the client cannot join the network.
• C. The router automatically adds the MAC to the whitelist.
• D. The router prompts for a password.

Answer: (B)

MAC address filtering with a whitelist allows only devices whose hardware addresses are on the approved list to connect. If a client’s MAC isn’t on that list, the router blocks the connection at the authentication/association stage, so the device cannot join the network. No IP address is assigned, no data session is established, and there’s no password prompt—MAC filtering operates independently of WPA credentials. Note that this is a basic form of control and can be bypassed by MAC spoofing, so it’s not a strong security measure on its own.